A typical cellular communication system includes one or more base stations (BS) and multiple mobile stations, as shown in FIG. 1. Each BS defines a cell of coverage, where each mobile station (MS) can communicate with a BS via a BS-MS link while within communication range of the BS cell coverage. In many cellular systems, radio resource management (RRM) for orthogonal frequency division multiple access (OFDMA)-based cellular systems are utilized. Such systems address resource allocations (e.g., frequency, time, power), among BS-MS links (i.e., transmission channels defined by frequency carriers, spreading codes or time slots). There are two types of RRMs: intra-cell RRM and inter-cell RRM. The intra-cell RRM tries to assign resources to MSs or BS-MS links within a cell (and prevent interference among MSs). The inter-cell RRM tries to assign resources to multiple cells (and prevent interference among BSs and MSs in different cells).
Intermediate relay stations (RS) have been used for improving throughput, coverage and spectrum efficiency of cellular systems. FIG. 2 shows an example cellular system including a base station BS and multiple mobile stations (MSs) and relay stations (RS1, . . . , RS6). A two-hop transmission takes place between a BS and MS via a RS, wherein an RS may be an MS itself. The introduction of relay stations brings forth new challenges to RRM for cellular systems. RRM for relay enhanced cellular (REC) systems has to address resource allocations among BS-MS, BS-RS, and RS-MS communication links.
In a REC system, there are two types of cells: BS cells and relay cells. Relay cells that are well separated from each other may reuse subcarriers in their access links.
In order to support relay stations, communication time frames can be divided into access zones and relay zones. Access zones and relay zones are defined in time domain. Relay stations (RSs) communicate with MSs in access zones and communicate with BS in relay zones. Conventional resource management approaches allow a BS to communicate with direct MSs in both access zones and relay zones, however at considerable complexity.